904 resultados para Explosive regimes


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In this paper, we propose a class of ACD-type models that accommodates overdispersion, intermittent dynamics, multiple regimes, and sign and size asymmetries in financial durations. In particular, our functional coefficient autoregressive conditional duration (FC-ACD) model relies on a smooth-transition autoregressive specification. The motivation lies on the fact that the latter yields a universal approximation if one lets the number of regimes grows without bound. After establishing that the sufficient conditions for strict stationarity do not exclude explosive regimes, we address model identifiability as well as the existence, consistency, and asymptotic normality of the quasi-maximum likelihood (QML) estimator for the FC-ACD model with a fixed number of regimes. In addition, we also discuss how to consistently estimate using a sieve approach a semiparametric variant of the FC-ACD model that takes the number of regimes to infinity. An empirical illustration indicates that our functional coefficient model is flexible enough to model IBM price durations.

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Measurements of explosive nucleosynthesis yields in core-collapse supernovae provide tests for explosion models. We investigate constraints on explosive conditions derivable from measured amounts of nickel and iron after radioactive decays using nucleosynthesis networks with parameterized thermodynamic trajectories. The Ni/Fe ratio is for most regimes dominated by the production ratio of Ni-58/(Fe-54 + Ni-56), which tends to grow with higher neutron excess and with higher entropy. For SN 2012ec, a supernova (SN) that produced a Ni/Fe ratio of 3.4 +/- 1.2 times solar, we find that burning of a fuel with neutron excess eta approximate to 6 x 10(-3) is required. Unless the progenitor metallicity is over five times solar, the only layer in the progenitor with such a neutron excess is the silicon shell. SNe producing large amounts of stable nickel thus suggest that this deep-lying layer can be, at least partially, ejected in the explosion. We find that common spherically symmetric models of M-ZAMS less than or similar to 13 M-circle dot stars exploding with a delay time of less than one second (M-cut < 1.5 M-circle dot) are able to achieve such silicon-shell ejection. SNe that produce solar or subsolar Ni/Fe ratios, such as SN 1987A, must instead have burnt and ejected only oxygen-shell material, which allows a lower limit to the mass cut to be set. Finally, we find that the extreme Ni/Fe value of 60-75 times solar derived for the Crab cannot be reproduced by any realistic entropy burning outside the iron core, and neutrino-neutronization obtained in electron capture models remains the only viable explanation.

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Ancient lakes are often unusually species rich, mostly as a result of radiation and species-flock formation having taken place in only one or a few of many taxa present. Understanding why some taxa radiate and others do not is at the heart of understanding biodiversity. In this chapter I discuss possible explanations for disproportionally large species numbers in some cichlid fish lineages in East African Great Lakes: the halochromine cichlid fishes in Lakes Victoria and Malawi. I show that speciation rates in this group are higher than in any other lacustrine fish radiation. Against this background, I review hypotheses put forward to explain diversity in cichlid species flocks. The evolution of species diversity requires three processes: speciation, ecological radiation and anatomical diversification, and it is wrong to consider hypotheses that are relevant to different processes as alternatives to each other. The African cichlid species flocks show unusually high ecological species packing in several phylogenetic groups and unusually high speciation rates in haplochromines. Therefore, it maybe concluded that at least two evolutionary models are required to explain the difference between cichlid diversity and other fish diversity in East African Lakes: one for speciation in haplochromines and one for coexistence. Subsequently I review work on speciation in haplochromines, and in particular studies aimed at testing the hypothesis of speciation by sexual selection. Haplochromines have a polygynous mating system, conducive to sexual selection, but other polygynous cichlids are not particularly species rich. This suggests that more than just strong sexual selection is required to explain haplochromine species richness. Recent palaeoecological evidence undermines the previously popular hypotheses that explained the species richness of Lake Victoria in terms of speciation under varying natural or sexual selection regimes in satellite lakes or in isolated lake basins. I summarize experimental and comparative studies, which provide evidence for two mechanisms of sympatric speciation by disruptive sexual selection on polymorphic coloration. Such modes of speciation may explain (i) the high speciation rates in colour polymorphic lineages of haplochromine cichlids under conditions where colour variation is visible in clear water, and (ii) in combination with factors that affect population survival, the unusual species richness in haplochromine species flocks. I argue that sexual selection, if disruptive, can accelerate the pace of adaptive radiation because the resultant genetic population fragmentation allows a much increased rate of differential response to disruptive natural selection. Hence, the ecological pattern of diversity resembles that produced by disruptive natural selection, with the difference that disruptive sexual selection continues to cause (gross) speciation even after niche space is saturated. This may explain the unusually high numbers of very closely related and ecologically similar species in haplochromine species flocks. The role of disruptive sexual selection is twofold: it not only causes speciation, but also maintains reproductive isolation in sympatry between species that have evolved in sympatry or allopatry. Therefore, the maintenance of diversity in species flocks that originated through sexual selection depends on the persistence of the selection regime within the environmental signal space under which that diversity evolved.

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The end of the recent Communist occupation of the many countries bordering Russia marked an end to the tyranny of illegal and forced annexation. Amid these countries are my parents’ homelands, the small Baltic nations of Latvia and Estonia. Their occupation contravenes many of the numerous Articles listed by The Office of the High Commissioner for Human Rights in The Universal Declaration of Human Rights (2008), constituting many acts of violation. As a filmmaker, I was unusually incognizant of these events, despite my relationship to them. My parents never discussed the war, while during the ensuing Communist era, information was conspicuously absent. However, this lack of knowledge provided the incentive that compelled a journey of discovery that resulted in the making of Regimes and Rebels. This Masters project is presented is two parts. The film equates to 70% of the project (52 minutes in length), whilst the exegesis represents the remaining 30%. The film is a ‘human rights’, ‘video diary’ styled documentary film about the Communist occupation of my parents’ homelands, Latvia and Estonia, and the resonating effect of the occupation on our family living in Australia and family still living in the homelands. The production of the video diary is contextualised by this exegesis, which concurrently discusses the burgeoning video diary format as the basis for making a ‘human rights’ documentary film. A discussion about the latter genre of documentary film ensues, encompassing modes of representation, followed by various issues related to production including: issues of aesthetics, styles, digital media, lack of evidence and subjectivity analogous with both filmmaker and audience. Next, work by other filmmakers in the ‘human rights’ genre, linked to the proliferation of Communism in Europe, is discussed and analysed in terms of production and modes of representation. The exegesis ends with my experience as filmmaker and an analysis of factors that arose in making Regimes and Rebels.

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Explosive Revelations’ employs the device of the Hollywood-style explosion to expose the constructed and futile nature of the moving image. Pointless, impotent explosions bloom and fade, punctuating a non-existent narrative – they promise the spectacle of violence but destroy nothing and disappear without a trace. The video itself is sourced from a stock footage supplier that provides users with a selection of explosions that can be inserted into movies by masking out the background. However, the footage is not used as intended, leaving them instead as merely explosions erupting on top of a black background, fizzling out into non-existence. The work was included in the 2008 'Light in Winter' program at Federation Square, Melbourne, directed by Robyn Archer.

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Airports and cities inevitably recognise the value that each brings the other; however, the separation in decision-making authority for what to build, where, when and how provides a conundrum for both parties. Airports often want a say in what is developed outside of the airport fence, and cities often want a say in what is developed inside the airport fence. Defining how much of a say airports and cities have in decisions beyond their jurisdictional control is likely to be a topic that continues so long as airports and cities maintain separate formal decision-making processes for what to build, where, when and how. However, the recent Green and White Papers for a new National Aviation Policy have made early inroads to formalising relationships between Australia’s major airports and their host cities. At present, no clear indication (within practice or literature) is evident to the appropriateness of different governance arrangements for decisions to develop in situations that bring together the opposing strategic interests of airports and cities; thus leaving decisions for infrastructure development as complex decision-making spaces that hold airport and city/regional interests at stake. The line of enquiry is motivated by a lack of empirical research on networked decision-making domains outside of the realm of institutional theorists (Agranoff & McGuire, 2001; Provan, Fish & Sydow, 2007). That is, governance literature has remained focused towards abstract conceptualisations of organisation, without focusing on the minutia of how organisation influences action in real-world applications. A recent study by Black (2008) has provided an initial foothold for governance researchers into networked decision-making domains. This study builds upon Black’s (2008) work by aiming to explore and understand the problem space of making decisions subjected to complex jurisdictional and relational interdependencies. That is, the research examines the formal and informal structures, relationships, and forums that operationalise debates and interactions between decision-making actors as they vie for influence over deciding what to build, where, when and how in airport-proximal development projects. The research mobilises a mixture of qualitative and quantitative methods to examine three embedded cases of airport-proximal development from a network governance perspective. Findings from the research provide a new understanding to the ways in which informal actor networks underpin and combine with formal decision-making networks to create new (or realigned) governance spaces that facilitate decision-making during complex phases of development planning. The research is timely, and responds well to Isett, Mergel, LeRoux, Mischen and Rethemeyer’s (2011) recent critique of limitations within current network governance literature, specifically to their noted absence of empirical studies that acknowledge and interrogate the simultaneity of formal and informal network structures within network governance arrangements (Isett et al., 2011, pp. 162-166). The combination of social network analysis (SNA) techniques and thematic enquiry has enabled findings to document and interpret the ways in which decision-making actors organise to overcome complex problems for planning infrastructure. An innovative approach to using association networks has been used to provide insights to the importance of the different ways actors interact with one another, thus providing a simple yet valuable addition to the increasingly popular discipline of SNA. The research also identifies when and how different types of networks (i.e. formal and informal) are able to overcome currently known limitations to network governance (see McGuire & Agranoff, 2011), thus adding depth to the emerging body of network governance literature surrounding limitations to network ways of working (i.e. Rhodes, 1997a; Keast & Brown, 2002; Rethemeyer & Hatmaker, 2008; McGuire & Agranoff, 2011). Contributions are made to practice via the provision of a timely understanding of how horizontal fora between airports and their regions are used, particularly in the context of how they reframe the governance of decision-making for airport-proximal infrastructure development. This new understanding will enable government and industry actors to better understand the structural impacts of governance arrangements before they design or adopt them, particularly for factors such as efficiency of information, oversight, and responsiveness to change.

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In this chapter I review the history of copyright in Australia through a singular and exemplary ruling of the Australian High Court made in 2012 and then relate that to the declining fortunes of Australian recorded music professionals. The case in point is Phonographic Performance Company [PPCA] of Australia Limited v Commonwealth of Australia [2012] HCA 8 (hereafter, HCA 8 2012). The case encapsulates the history of copyright law in Australia, with the judicial decision drawing substantive parts of its rationale from the Statute of Anne (8 Anne, c. 19, 1710), as well as copyright acts that regulated the Australian markets prior to 1968. More importantly the High Court decision serves to delineate some important political economic aspects of the recorded music professional in Australia and demonstrates Attali’s (1985) assertion that copyright is the mechanism through which composers are, by statute, literally excluded from capitalistic engagement as ‘productive labour’.

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Adaptation is increasingly being viewed as a necessary response tool in respect of climate change effects. Though the subject of significant scholarly and professional attention, adaptation still continues to lag behind mitigation in the climate change discourse. However, this situation looks likely to change over the coming years due to a increasing scientific acceptance that certain climate change effects are now inevitable. The purpose of this research is to illustrate, consider and demonstrate how urban planning regimes can use some of their professional tools to develop adaptation strategies and interventions in urban systems. These tools include plan-making, development management, urban design and place-making. Urban systems contribute disproportionately to climate change and will also likely suffer considerably from the resulting effects. Moreover, the majority of the world’s population is now urbanised, suggesting that adaptation will be crucial in order to develop urban systems that are resilient to climate change effects. Informed by a reflexive, qualitative methodology, this paper offers an informed understanding and illustration of adaptation as a climate change response, its use in urban systems and some of the roles and strategies that planning may take in developing and implementing urban adaptation. It concludes that urban planning regimes can have key roles in adapting urban systems to numerous climate change effects.

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Explosive ordnance disposal (EOD) technicians are required to wear protective clothing to protect themselves from the threat of overpressure, fragmentation, impact and heat. The engineering requirements to minimise these threats results in an extremely heavy and cumbersome clothing ensemble that increases the internal heat generation of the wearer, while the clothing’s thermal properties reduce heat dissipation. This study aimed to evaluate the heat strain encountered wearing EOD protective clothing in simulated environmental extremes across a range of differing work intensities. Eight healthy males [age 25±6 years (mean ± sd), height 180±7 cm, body mass 79±9 kg, V˙O2max 57±6 ml.kg−1.min−1] undertook nine trials while wearing an EOD9 suit (weighing 33.4 kg). The trials involved walking on a treadmill at 2.5, 4 and 5.5 km⋅h−1 at each of the following environmental conditions, 21, 30 and 37°C wet bulb globe temperature (WBGT) in a randomised controlled crossover design. The trials were ceased if the participants’ core temperature reached 39°C, if heart rate exceeded 90% of maximum, if walking time reached 60 minutes or due to fatigue/nausea. Tolerance times ranged from 10–60 minutes and were significantly reduced in the higher walking speeds and environmental conditions. In a total of 15 trials (21%) participants completed 60 minutes of walking; however, this was predominantly at the slower walking speeds in the 21°C WBGT environment. Of the remaining 57 trials, 50 were ceased, due to attainment of 90% maximal heart rate. These near maximal heart rates resulted in moderate-high levels of physiological strain in all trials, despite core temperature only reaching 39°C in one of the 72 trials.

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“Supermax” prisons, conceived by the United States in the early 1980s, are typically reserved for convicted political criminals such as terrorists and spies and for other inmates who are considered to pose a serious ongoing threat to the wider community, to the security of correctional institutions, or to the safety of other inmates. Prisoners are usually restricted to their cells for up to twenty-three hours a day and typically have minimal contact with other inmates and correctional staff. Not only does the Federal Bureau of Prisons operate one of these facilities, but almost every state has either a supermax wing or stand-alone supermax prison. The Globalization of Supermax Prisons examines why nine advanced industrialized countries have adopted the supermax prototype, paying particular attention to the economic, social, and political processes that have affected each state. Featuring essays that look at the U.S.-run prisons of Abu Ghraib and Guantanemo, this collection seeks to determine if the American model is the basis for the establishment of these facilities and considers such issues as the support or opposition to the building of a supermax and why opposition efforts failed; the allegation of human rights abuses within these prisons; and the extent to which the decision to build a supermax was influenced by developments in the United States. Additionally, contributors address such domestic matters as the role of crime rates, media sensationalism, and terrorism in each country’s decision to build a supermax prison.

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The conflicts in Iraq and Afghanistan have been epitomized by the insurgents’ use of the improvised explosive device against vehicle-borne security forces. These weapons, capable of causing multiple severely injured casualties in a single incident, pose the most prevalent single threat to Coalition troops operating in the region. Improvements in personal protection and medical care have resulted in increasing numbers of casualties surviving with complex lower limb injuries, often leading to long-term disability. Thus, there exists an urgent requirement to investigate and mitigate against the mechanism of extremity injury caused by these devices. This will necessitate an ontological approach, linking molecular, cellular and tissue interaction to physiological dysfunction. This can only be achieved via a collaborative approach between clinicians, natural scientists and engineers, combining physical and numerical modelling tools with clinical data from the battlefield. In this article, we compile existing knowledge on the effects of explosions on skeletal injury, review and critique relevant experimental and computational research related to lower limb injury and damage and propose research foci required to drive the development of future mitigation technologies.